Valve-gear fob



UNIE STATES PATENT OFFIOE.

ELIJAH WARE, OF SOUTH BOSTON, MASSACHUSETTS.

VALVE-GEAR FOR STEAM-ENGINES.

Specication of Letters Patent No. 23,629, dated April 12, 1859.

To all whom it may concern:

Be it known that I, ELIJAH VARE, of South Boston, in the county ofSuffolk and State of Massachusetts, have invented a new and ImprovedValve-Gear for Locomotive and other Steam Engines; and I do herebydeclare that the following is a full, clear, and exact description ofthe same, reference being had to the accompanying drawing, forming partof this specification, said drawing representing a side view of myimproved valve-gear as adapted to the locomotive-engine.

This invention consists in a novel means of connecting the eccentric rodwith the valve rock-shaft, or its equivalent, for the purpose ofenabling the stroke of the valve to be varied to vary the point ofcutting off the steam from the cylinder of an engine.

It also consists in a novel combination of mechanism through whoseagency the operation of the slide or other valve or system of valves'employed in a steam engine, is effected by means of a single eccentric,which, without ever being shifted upon the shaft, is made to work thevalves for running the engine in either direction, and to vary themovement of the valve for'cutting off the steam at different points inthe stroke of the engine.

To enable others skilled in the art to make and use my invention, I willproceed to describe its construction and operation.

A, is the driving axle or crank-shaft of the engine.

B, is the crank, and C, is the valve eccentric which is keyed firmly to-the shaft and whose position may coincide with or be directly oppositeto that of the crank, according to the nature of the valve connections,but whic'h is represented in the lirst named position.

F, is the valve seat, and E, the valve, which is of the short D kind andmade with a lap and which is connected with the arm a, of the rock shaftGr, which works in fixed bearings on the frame of the engine, and whichderives its rocking movement from an eccentric through the agency of themechanism which constitutes my invention.

H, is the eccentric rod connecting the eccentric C, with a three-armedlever I, which works on a fixed fulcrum pin l), secured in the framingof the engine, and which is connected by a rod J, with the arm c, of thevalve rock-shaft G, to operate the valve by the revolution of theeccentric. The lever I, contains two arc-formed slots d, and e, theformerwhich extends nearly the whole length of one armto receive a pinf, secured to the eccentric rod H, and the latter which extends nearlythe whole length of two arms-to receive a pin g, secured to the rod J.The arc of the slot d, is described with a radius equal to the distanceof the pin j", from the center of the eccentric O, and the arc of theslot e, with a radius equal to the working length of the rod J, and thetwo arcs and fulcrum pin Z), are severally so arranged permanently inrelation to each other that in the movements of the lever the said arcCZ, deviates as little as possible from a position concentric to thecenter of the eccentric, and the said arc e, deviates as little aspossible from a position concentric to the pin h, which attaches the rodJ, to the arm o, of the valve rockshaft. The slots d, and e, are topermit the changing of the positions of the pins f, and g, relatively tothe fulcrum b, to vary the stroke of the valve and the point of cut onand for reversing the engine, and for these purposes the means ofshifting the said pins in the said slots are as follows.

The pin f, is also received within a slot z', in a lever K, which istted to swing loosely on the shaft or crank axle A, and which isconnected by a rod L, with what I term a secondary lever O, attached bya fulcrum pin j, to the arm N, of a lever M N, which works on a fixedfulcrum ,70, secured in the frame of the engine, and the pin g, isconnected by a rod P, with t-he arm M, of the said lever M N. The sloti, is of a length to permit the stroke of the eccentric rod. The arm N,is connected by a rod m, with a hand lever Q, which works on a fixedfulcrum n, and which is conveniently situated to be operated by theengineer, and which is fitted with a catch or bolt which is capable ofentering either one of two series of notches 79, p, in a stationary arcR, and thereby locking the lever Q, in various positions. The secondarylever O, has attached to it a pinion u, which is concentric with itsfulcrum 7c, and this pinion gears with a toothed are S, attached rigidlyto a lever T, which is arranged to move on the same fulcrum 7e, as thelever M N. This lever T, is connected by a rod U, with a hand lever V,which is arranged to work on the same fulcrum n., as the hand lever Q.This lever V, has atthe valve, and consequently the point of cut off,depends upon the relative distances of the pins f, and g, from thefulcrum Z). When the pin g, is below' the fulcrum as represented, thevalve will be so operated that the direction of the revolution of thecrank will be as indicated by the arrow shown near it in the drawing. Toplace the said pin g, above the fulcrum to reverse it, the

lever Q, is moved to the opposite end of the arc piece g, of the lever,and the pin s, secured in the notch r, and in this movementthe pin t, isshifted from one of the notches p, p, to one of those, p1, p1, near theother end of the crank R. The leverQ, in this movement acts through therod m, lever M N, and rod P, to raise the pin g, and the movement of thepinion u, along with the lever M, with its teeth in gear with the arc S,causes the said pinion to make half a revolution on the fulcrum pin j,and shift the secondary lever O, to the position indicated in red colorin the drawing and thus by its action through the rod L, on the lever K,to shift the pin y", and eccentric rod H, toward the fulcrum b. Thereason for having the pin f, to shift along with the pin g, in thismovement is not that it is so necessary for the reversal alone, but thatthe reversal and change of stroke could not both be effected by the mereshifting of the pins f, and g, or either of them, without it'. Theportion of the slot e, below the fulcrum requires to be much longer thanthe portion above, as when the pin g, is in the lower part, the pin f,is nearer the fulcrum Z).

To vary the length of stroke of the valve, and thus vary to some extentthe cut off point, the lever Q, is shifted to change the pin from one toanother of the notches p, p, or p1, 201, but never moved past the middleof the arc from one notch p, to one p1, or vice versa, and thismovement, by changingA the relative distances of the pins f, and g, fromthe fulcrum b, effects a variation in the length of stroke of the valvewithout eii'ecting any change in the position relatively to the piston,at which the valve commences to open the ports and admit steam.

It may be observed in the drawings that theV fulcrums la, and I), areboth secured in a kneed frame VV which is arranged to vibrate at itsknee upon a fixed pin w, secured in the main frame of the engine andwhich is connected with the shaft or driving axle A, in such a manner asto cause it to vibrate with the said shaft or axle, as the latter is, ormay be caused to move up and down by the passage of the locomotive overthe track. This frame lV, will be dispensed with in a stationary engineand the fulcrums 7G, and b, will be attached to the main framing.

In adapting the improvement to stationary engines the levers Q, and V,and all their connections with the pins f, and `g, may be dispensed withand the said pins lboth connected with the governor for the purpose ofgoverning the speed of the engine by varying the stroke of the slidevalve.

The same valve gear either with or without the combination of reversinglevers Q, V, may be adapted to puppet valve engines by substituting forthe arm a, of the valve rock-shaft G, two toes, as shown in the drawingin blue outline.

lVhat I claim as my invention and desire to secure by Letters Patentisl. Combining the eccentric rod with the valve rockshaft G, or itsequivalent by means of the lever I, with its two arc-formed slots cl, e,and the movable pins 7", g, the whole applied and operatingsubstantially as and for the purpose herein specified.

2. And I also claim the combination with the double slotted lever I, andits movable pins f, g, of the levers Q., V, rods m, U, levers M N, andT, secondary lever O, pinion u, toothed arc S, and rods L, P, the wholeapplied and operating substantially as and for the purpose hereindescribed.

. ELIJAH VARE. lVitnesses NIARTHA A. WARE, EMLINE SIMPSON.

